Cath Kidston, the high street queen of florals, has banked a second fortune from her eponymous homewares empire.

The London-based designer and her business partners TA Associates are in line for multimillion-pound payouts after selling a "substantial" number of shares to an Asian private equity house. It is the second time the entrepreneur, famous for her chintzy fabrics and retro kitchenware, has sold down her stake in the company.

The deal is thought to have valued the British retailer at close to £250m, making Kidston's personal holding worth around £50m. It is not clear how big a chunk she has sold but TA Associates and Hong Kong based Baring Private Equity Asia now own equal stakes in the business with the management team sitting on a reduced minority holding.

Kidston's teapots and oilcloths, which embrace the image of the 1950s housewife, celebrating baking, afternoon tea and knitting, were a surprise high street hit that has now been successfully exported as far afield as Hong Kong, Indonesia, Japan, Korea and Malaysia. The rationale behind the deal is to capitalise on soaring demand in Asia with the company pointing to research that indicates Chinese workers migrating to its cities have the same hankering for the country life that has fuelled the retro brand's popularity here.

Kidston is aware that her polka dot plates and cabbage rose tea towels evoke a "marmite reaction", telling one interviewer: "People either love it and want a little bit of it very much, or want to stab us."

But the first camp are clearly in the ascendence with the success of the business reflected in the hefty price tag. Kidston also made millions of pounds back in 2010 when TA Associates bought a controlling stake in a deal which then valued the company at around £100m.

The sale is another stepping stone in Cath Kidston's journey from a single store in London's upmarket Holland Park, selling vintage wallpaper and brightly painted furniture, to Cath Kidston Inc with 166 stores around the world and a turnover of £144m.

In a rare interview with Red magazine last year, Kidston – who is the cousin of rival style guru Kirstie Allsopp – said the aesthetic was inspired by happy memories of her childhood in Hampshire. When she opened her first shop in 1993: "No one was selling these things. There was no such thing as a flowery ironing board. I found a shop with cheap rent and no deposit – you could do that in those days."

Billed as a modern day Laura Ashley, Kidston's heavy floral prints have become as ubiquitous in the UK over the last decade as Ashley's romantic prints were in the 70s. The domestic chain has 66 stores with the brand in danger of reaching saturation after giving everything from Millets' tents to Sky boxes and Tesco carrier bags the floral treatment. It has no plans for additional UK stores but the great white hope is mainland China where it has ambitions to open 100 oulets.

Kenny Wilson, Cath Kidston's chief executive, said: "Finding the right partner to help us manage the development of the Cath Kidston brand in Asia, and in particular to exploit its potential in China, was a key consideration for us. Baring Asia's support and operational experience will be invaluable as we expand."

Baring Asia specialises in bringing western brands to China, having previously bought companies such as private school group Nord Anglia Education and a stake in the Indian arm of French concrete manufacturer Lafarge. "The Cath Kidston brand has demonstrated its significant appeal and established a strong following in Asia," said Dar Chen, a managing director at Baring Asia.